ABSTRACT
It is a matter of some disagreement exactly when the ‘professional’ Roman army came into being. It is generally agreed that the army of the third and second century BC was an amateur citizen militia with troops raised on an annual basis from the whole body of Roman citizen men. These troops served for the duration of the campaign (ideally a single year) before returning to their pre-enlistment professions. It is also accepted that the army of the mid-first century AD, about which we know a great deal from literary and documentary sources, was much closer to what we would now characterise as a professional army with troops serving for twenty or twenty-five years. Historians have traditionally placed this fundamental change in the nature of Rome’s armed forces at the end of the second century BC and have associated this development with the great Republican general Marius. More recently, the extent to which Marius changed the army has been questioned and historians have pointed to continuities between the army of the mid-second century BC and that of Caesar. It is becoming increasingly clear that, although the army can be seen to play a more direct role in politics in the first century BC, the institutional structures which transformed the army were only gradually put in place and that far-reaching changes were instituted during the reign of Augustus. Many of the Augustan reforms were not yet properly operational by AD 14 and there were important changes in the army’s organisational structure after this date. Nevertheless, Augustus developed the framework for the later army. He established terms and conditions of service, the legal framework which governed the soldiers while in service, the benefits which the soldiers received on discharge, the standing units into which the soldiers were recruited, the fiscal system which was to pay for the troops, the political framework in which the army was to operate, and he developed (though it is unclear quite what is Augustan) the auxiliary system (see below).
